Humidifier and deodorizer



J1me 1965 E. J. MCELREATH 3,190,624

HUMIDIFIER AND DEODORI ZER Filed July 6, 1961 I s sheets-sheet 1 June 22, 1965 E. J. MCELREATH 3,190,624

HUMIDIFIER AND DEODORIZE'R Filed July 6, 1961 3 Sheets-Sheet 2 INV EN TOR.

J1me 1965 E. J. MOELREATH HUMIDIFIER AND DEODORIZER 3 Sheets-Sheet 3 Filed July 6,.1961

w, m/ M,

United States Patent Ofifice 3,19%,624; Patented June 22, 1965 3,190,624 HUMlD-IFHER AND DEODORHZER Elmer .l. McElreath, Glen Eilyn, EL, assignor to Hamilton Humidity, inc, Chicago, ill., a' corporation of Illinois Filed duly 6, 1961, Ser. No. 122,3ll3 7 Claims. (til. 26lt--92) This invention relates to improvements in humidifiers and deodorizers of the type in which a member is movable into a water reservoir to absorb water and then into an air stream for evaporation of the water by the impinging air.

Commercially available humidifiers fall into two general categories. The first type provides for the absorption of water from a reservoir and placing the water in an air stream for the evaporation of the water. These devices have been characterized in the past by particularly poor evaporation eificiency either initially or at least after a considerable period or" use.

The other type is one in which the water is atomized into a vapor form mechanically, for example, by the application of very high centrifugal forces, and an air stream is passed through the chamber in which the atomized vapor appears to carry the vapor with it from the chamber. This latter type of humidifier has been ch racterized in all known devices by the undesirable feature of causing deposits of moisture and lime in the vicinity of the humidifier, which is particularly troublesome in portable room humidifiers.

The present invention is directed specifically to the evaporation type humidifier. There have been innumerable attempts to provide a commercially satisfactory evaporative humidifier, both of the portable type and of the type which is readily adapted for installation in new and existing home and commercial furnace installations. It is of primary importance to provide a compact, very etficient unit which is low in cost, and this is especially true in the furnace type installation for the average home.

At first glance, it would appear that the problem would lend itself to a ready solution; yet over the many years during which the innumerable attempts have been made, no one so far as is known has been successful in marketing a truly satisfactory humidifier of this type which is very efiicient in operation for a long period of time, which can be provided at a reasonably low cost, and which is compact without sacrificing an appreciable loss in the mass rate flow of air.

So far as is known, all of the prior attempts to substantially increase the efficiency of evaporation of a humidifier have resulted in a serious loss in air flow. As a result, it necessitated the provision of a substantially greater air fiow rate in new furnace installations; and on the other hand, where the humidifier was added to an existing installation, the cost of increasing the air flow rate was usually prohibitive, and a substantial loss in air flow was tolerated as a penalty for achieving the greater evaporation efiiciency.

An even more serious related problem confronted the designers of evaporative humidifiers when it was recognized that, with continuous use of the humidifier over a period of time, the depositing of lime on the water absorbing portion of the humidifier leads in time to the ineffectiveness of the humidifier. The lime deposits eventually prevent the absorption of a sutiicient quantity of water from the reservoir, and for all intents and purposes the humidifier is relatively worthless unless a completely new water absorbing portion is provided.

Accordingly, it is a primary object of the present invention to provide an improved evaporative type humidifier which is compact, low in cost and unusually efficient in relation to its size.

It is another object of the present invention to provide an evaporative type humidifier of the type described in the preceding object in which the flow of air through the humidifier is substantially unaffected without any resulting penalty in etficiency of evaporation. These objects are accomplished in the preferred embodiment of the invention by mounting a plurality of screen wire disks on a shaft which is transverse to the air flow with the disks being positioned in planes forming a small angle with a plane transverse to the aXis of the shaft. As the disks are rotated with the shaft at a very slow rate, their lower portions are submerged in a reservoir of water and are then rotated laden with water into the air stream. With this arrangement the angle which the fiat surfaces of the disks form with the air path is continually varying though only a slight amount, whereby a very small amount of air turbulence is created to substantially increase the efficiency of evaporation without any noticeable effect on the rate of air flow.

Accordingly, it is an object or" the invention to provide an evaporative type humidifier in which water absorbing disks are rotated with their lower portions submerged in a water reservoir and with their upper portions subjected to an air stream for evaporation of the water, characterized by the positioning of the disks on an axis transverse to the air flow with the disks positioned in planes forming a small angle with a plane transverse to the axis.

Initial home furnace models using generally circular disks of screen wire were observed in operation; and it was noted that, for the major portion or" the time, the water was evaporated primarily along only the outer peripheral edges of the disks. This suggested the pos sibility that there might be some relationship between the edge surface of the disks and the efficiency of evaporation. It Was readily apparent that space limitations did not permit the enlargement of the apparatus since the size of the hot air duct to which the humidifier was attached defined the limits of the size of the disks and the areas of the disks which could be placed in the air stream laden with water. Increasing the number of disks would restrict air flow. As a result, slots generally in the form of sectors were cut from the disks to increase the edge area thereof without increasing the diameter of the disks. It was found that the slots in the disks provided a substantially increased efiiciency of operation with no notice- ;ble penalty in size, additional cost or reduction in air row.

It was also noted that the deposit of lime on the screen wire disks was substantially reduced after the slots had been cut in the screens. Continued observation led to the realization that the disks, slightly weakened by the slots therein, fluttered or vibrated a slight bit when subjected to the air stream. Further investigation led to the conclusion that the fluttering of the screens continuously during the operation of the humidifier caused a loosening of the lime deposits as they were being formed during evaporation. It will be appreciated that the deposits are formed only when the water in which the lime is entrainexl is evaporated; and, since the screens are fluttering continuously during the evaporation process, the lime does not adhere securely to the screens. As the screen portions with the loosely adhering lime deposits subsequently move through the water bath, at least a portion of the deposits is removed by the water to settle out in the bottom of the reservoir. As a result, a very unique and simple method for self cleaning of the screen wire disks was provided and at no additional cost.

It is another object of the present invention to provide a humidifier of the type described in the preceding object in which the disks are arranged in groups with the posiarsena a tions of the disks in the groups being staggered angularly with respect to each other, whereby a substantially constant, very low resistance to air flow is provided as well as a substantially constant load on the drive means for the disks and a substantially constant rate of evaporation.

Another object of the present invention is the provision of an evaporative type humidifier characterized by radially slotted water absorbing disks, the lower portions of which are submerged in a water reservoir and the upper portions of which are placed in an evaporating air stream.

Another object is the provision in an evaporative humidifier of an improved means for maintaining the water absorbing elements substantially free of lime deposits.

It is a more specific object of the present invention to provide an evaporative type humidifier of the type in which water absorbing disks have their lower portions submerged in a. water reservoir and their upper portions positioned in an air stream wherein the disks are permitted to flutter slightly for the substantial removal of lime deposits therefrom.

It is another object of the present invention to provide an improved means sensitive to the flow of air for turning the humidifier on and off.

It is another object of the present invention to provide a unitary humidifier structure easily installed in an existing furnace installation, readily detachable and easily disassembled for ease of installation and maintenance.

It is another object of the present invention to provide a humidifier which is very versatile in its application to various portions of an existing furnace installation.

It is another object of the present invention to provide a very compact and highly efficient portable humidifier.

It is another object of the present invention to provide an evaporative type humidifier which readily lends itself to the provision of air deodorizing and germicidal features.

Other objects and the many features of the invention will be readily apparent upon a perusal of the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a fragmentary elevation view of one form of the improved humidifier connected to an overhead hot air duct of a furnace installation;

FIG. 2 is a fragmentary plan view partially in section of the improved humidifier substantially along line 22 of FIG. 1;

FIG. 3 is a fragmentary elevation view of the improved humidifier partially in section substantially along line 33 of FIG. 1;

FIG. 4 is a fragmentary elevation view substantially along line 4-4 of FIG. 3 showing the preferred switch for energizing and deenergizing the humidifier motor;

FIG. 5 is a plan view of a preferred form of the water absorbing disk;

FIG. 6 is a fragmentary elevation view partially broken away showing a second form of the improved humidifier installed on the vertical wall of the bonnet of a furnace;

FIG. 7 is a fragmentary elevation view of the humidi fier of FIG. 6 substantially along line 77 of FIG. 6;

FIG. 8 is a sectional plan view of a third, portable embodiment of the improved humidifier;

FIG. 9 is a fragmentary plan view of a fourth embodiment of the invention; and

FIGS. 10 and 11 are fragmentary side and end elevation views of a fifth, portable embodiment of the improved humidifier.

In FIGS. 1-5 inclusive, a humidifier 10 is carried by a hot air duct 12 of a furnace installation (not shown except that a portion of the furnace plenum chamber is indicated at 11) secured to an overhead supporting structure 14 by means of straps 16. The furnace installation contemplated is of the ordinary forced hot air type in which a ventilating air blower, supplied as a portion of the furnace equipment and therefore not shown, circulates hot air through the plenum chamber 11 and into the hot air duct 12 when the furnace is operating. The duct includes a lower horizontal wall 18 which has an aperture 2%) of generally rectangular shape cut therein. A generally rectangular brace member 22 having a rectangular opening 24 is secured to the lower wall 13 over the opening by means of screw and wing nut fastener assemblies 26.

The humidifier 10 includes a generally semi-cylindrical reservoir 36 having projections 32 and 34 projecting horizontally outwardly from the upper end thereof. Projections 32 and 34 include apertures (not shown) for mounting of the reservoir below the lower duct wall 18 by means of the fastener assemblies 26. The brace member 22 has a depending projection 36 which abuts tightly against the side wall 38 of the reservoir to accurately position the reservoir and to minimize vibration.

A. motor assembly 40 enclosed in a. housing .2 is received through an aperture in the projection 34 and is secured to the projection, for example, by means of welding. The motor assembly 40 includes a suitable s eed reduction gear assembly (not shown) to reduce the output speed of the motor assembly 41) to a relatively low value, for example, in the order of one to seven rpm. A typical output speed of 4.75 r.p.m. has been found to provide very satisfactory results in most installations. The motor assembly is connected to and drives a generally horizontal shaft 44 which is supported at its opposite end by means of a journal 46 secured to the side wall 38 of the reservoir.

A switch assembly 5% for controlling the motor assembly 46 includes a support arm 52 secured to the upper end of the housing 42, for example, by means of welding. The upper end of the arm 52 carries a pivot pin 54 upon which a generally U-shaped portion of a bracket 55 is pivotally mounted. The bracket 56 includes a downwardly depending arm 58 which is positioned in the air stream. A mercury switch 62, secured to the upper end of the bracket by a clamp 63, is normally tilted as shown in FIG. 4 when no air is flowing through the duct 12. When the switch 62 is in this tilted position, its pool of mercury (not shown) does not electrically interconnect the conductors 64 and 66. When hot air is being forced through the duct 12, by the furnace ventilating air blower (not shown but previously mentioned) it will impinge against the downwardly depending arm 58 to rotate the bracket 56 in a counterclockwise direction (FIG. 4) about the axis of the pin 54 to tilt the mercury switch 62 so that the pool of mercury electrically interconnects the wires 64 and 65 to turn the motor on. Thus a very simple automatic motor control is provided.

A plurality of generally circular screen wire disks 78 are carried by the shaft 44 in spaced relation to each other. Although the disks are preferably made of relatively inexpensive metallic screen wire, nevertheless it will be appreciated that other water absorbing materials may be utilized. As best seen in FIG. 5, the disk 70 has slots 72 generally in the form of sectors cut therefrom in angularly spaced positions for substantially increasing the peripheral edge length of the screen wire disks. As indicated earlier, this has been found to provide a substantially increased evaporation efiiciency without increasing the size of the disk.

The screens 79 are held in place and properly spaced by a plurality of generally cylindrical spacers '74 interposed between adjacent disks 70. The ends of the spacers are formed at an angle with respect to a plane normal to their axes, which angle corresponds to the desired angle which the disks form with the axis of the supporting shaft 44. In the embodiment of FIGS. 1-5, an angle of approximately 20 has been found to give very desirable results in terms of high efiiciency of evaporation without any appreciable restriction to the air flow. It will be appreciated, however, that the disks may be positioned normal to the axis of the shaft 44; however, in this position the humidifier does not have as high an efiiciency. Also it can be appreciated that'the angle which the disks form with the axis may be greater than but if it is too much greater, a point will be reached beyond which there will be a tendency to unduly restrict the air flow. In the preferred embodiment, the spacer bores form a tight fit with the shaft 44 so that they will be retained in place on the shaft by friction.

In FIG. 2, it will be noted that the diagonal ends of each of the spacers are parallel with the diagonal ends of all of the other spacers whereby all of the disks 70 are parallel.

As a result, each of the disks will cyclically vary the angle which it forms with the direction of air flow from zero degrees to 20 and back to zero degrees for each 180 rotation of the shaft 44. This cyclical action of the disks with respect to the air flow causes a slight turbulence in the air fiow through the disks. However, it is not sufiiciently great to cause any noticeable drop inpressure of the air and therefore no appreciable drop in the rate of air fiow. Although the rate ofevaporation varies due to this cyclical action, that is, the rate of evaporation is greater when the screens. form an angle of 20 with respect tothedirection of air flow than at zero degrees, it has been found that this does not appear to cause any noticeable variation in the end result of uniformly increasing the humidity in the building. The constant circulation of air at the rates encountered in the typical commercial and home furnace installation is such as to produce a relatively constant increase in humidity throughout the building.

If for any reason there should be a desire to maintain the momentary rate of evaporation at the humidifier relativcly constant, the disk arrangement of FIG. 8 which will be described in detail later may be substituted for the disk arrangement of FIG. 2. Briefly, the angular positions relative to the shaft 44 at which the disks form the angle of 20 are staggered angularly about the axis of the shaft so that at all times the composite of all of the disks present to .the air stream a relatively constant diagonal surface area.

The water level in the reservoir is maintained constant by means of a conventional float valve water regulator 76 which has an inlet feed system 78 and an outlet St) which is connected to a spud inlet 82 in the reservoir by means of a flexible hose 84. The regulator is secured to an L-shaped bracket 86 by means of a fastener assembly 88, and the bracket in turn is secured to a supporting angle iron 90 by means of a fastener assembly 92. The angle iron 90 is secured to the lower side of the projection 34 by means of one of the fastener assemblies 26.

The angle iron 99 has a vertical slot (not shown) through which the fastener assembly 92 is received, whereby the vertical position of the bracket 86 and the water level regulator 76 may be varied to adjust the water level in the reservoir to the desired height. This feature may be utilized to vary the rate of evaporation in the system since with a lower water level, less of the surface area of the disks 70 will pick up water and as a result the total amount of evaporation will be reduced. By running a few experimental tests over a sutficient period of time and by adjusting the water level to different heights, the optimum position of the water level may be determined for obtaining the desired humidity, for example in the building.

FIGS. 6 and 7 show a second embodiment of the invention especially adapted for mounting on the vertical wall 80 of the bonnet of a furnace (not shown). A sheet metal hood 82 enclosing the humidifier is secured to the wall 86 by means of fastener assemblies 84 received through the furnace wall and a peripheral flange 86 on the hood. The hood includes an irregularly shaped forward wall 38 and a pair of side walls 90, one of which supports a transparent window 92.

The humidifier apparatus of FIGS. 6 and 7 is the same as that shown in FIGS. 1-5, and similar reference characters with the suflix a are applied to the corresponding components. The details of the humidifier apparatus will therefore be described only as required for a clear understanding of the second embodiment. Thus the humidifier 1th: includes a generally semi-cylindrical water reservoir 3th: with horizontal projections 32a and 34a secured to angle irons'98 by fastener assemblies 101). The angle irons are secured to the side walls )0 by means of fastener assemblies 192.

In this embodiment, the humidifier is mounted outside of the hot air stream in the bonnet chamber to permit the installation of air conditioning equipment which is frequently installed therein. A portion of the rising hot air is directed to the humidifier 10a by means of a bafile or scoop 1%14 which projects a short distance into the bonnet chamber. The hot air is diverted by the baffie 194 at a slightly increased pressure and is directed through a passage 1% defined by the juxtaposed surfaces of the reservoir 30a and the hood 82 and thence through the upper portions of the disks 7% by a curved portion 1W on the forward wall of the hood.

The increase in pressure caused by the bafiie 1114 and the positive directing of the air stream through the disks by the curved surface 167 have been found to give a substantially improved efficiency of evaporation. This is particularly important since only a portion of the hot air is passed across the disks ma to entrain water vapor therein. The portion of the air which entrains water from the disks 7th: by evaporation is projected back into the main hot air stream in the bonnet chamber for admixture with the main air stream to substantially increase the humidity of all of the air passing through the bonnet.

FIG. 8 shows a third embodiment of the improved humidifier adapted for use as a portable humidifier. Thus the portable humidifier comprises a housing 112 having a generally rectangular base 114, side walls 116 and 118, end walls 120 and 122, and a cover (not shown). A pair of intermediate vertical walls or bafiles 124 and 125 are Welded to the side wall 116 and extend approximately three-fourths of the distance to the opposing side wall 118. A pair of intermediate walls or bafiies 126 and 128 are welded to the side wall 118 and project about three-fourths of the distance to the opposite side wall 116. The end walls 120 and 122 and the intermediate walls 124, 125, 126 and 1255 provide a circuitous path indicated by the arrows for air flow from an inlet opening 130 in the side wall 116 to an outlet opening 132 in the side wall 118.

A motor assembly 134 having reducing gears (not shown) is suitably mounted to the exterior of the end wall 120. A shaft 136 is connected to and supported at one end by the output 138 of the motor assembly, and the opposite end of the shaft is supported by a journal 140 suitably secured to the internal side of the end wall 122.

A T-shaped filler adapter 142 is secured through an aperture (not shown) adjacent the lower end of the side wall 121). The adapter is connected to a sight tube 144 and to a funnel 146. The sight tube 144 is utilized to indicate the level of the water in the housing 112 and additional water is added through the funnel 146.

The side wall 120 and the intermediate wall 124 support a vertical stack of electric heater elements 148 and a fan assembly 150 above the water level. Since this embodiment is portable, it is preferred to use an electric heating element for warming the incoming air, because the evaporation of the water has a cooling effect upon the air stream and the heating element tends to counteract this, so that the humidified air coming from the device is not unduly chilled. Heating the air also, of course, increases the rate of evaporation. The inlet 130 is preferably a circular opening generally coaxial with the axis of the fan assembly and includes a filter 152. A suitable grill 153 covers the outlet 132. In this embodiment, a switch responsive to the air flow for turning on the motor is not required since the motor and the fan assemblies are started simultaneously when fa plug 155, connected to the motor and fan by a cord, -is inserted in a suitable electric wall outlet (not shown).

A plurality of disks 154 are arranged in groups 156, 158, 165i, 162 and 164 between the adjacent end walls and intermediate walls. As in the previous embodiments, the disks are positioned and partially supported by a plurality of generally cylindrical spacers 166 with diagonal ends. However, in this embodiment, the angular positions, in which the ends of the spacers (and therefore the disks) form a desired angle with the axis of the shaft 136, are staggered angularly about the axis from group to group of disks. This staggering of the disks from group to group is achieved by merely angularly rotating those spacers associated with each group of disks about the axis of the shaft 136 a desired amount as will now be described.

Assume that all of the spacers 166 have their diagonal ends parallel, e.g. in the positions of the spacers for the disk group 156 in FIG. 8. The spacers associated with the group 158 are then angularly rotated about the axis of the shaft 124) approximately 22 /2. The spacers associated with the group 16f) are angularly rotated to a 45 position, those associated with group 162 to a 67 /2 position, and finally those associated with the group we at 90 position with respect to those associated with the group 156.

Since the planes of the disks 154 are determined by the diagonal ends of their spacers, they are similarly transposed angularly about the shaft axis. Thus as shown in FIG. 8, the disks in the group 156 have their surfaces fully exposed to the air passing between the side wall 12% and the intermediate wall 124 while the disks in group 164 are in positions generally parallel with the direction of air flow between the intermediate wall 128 and the side wall 122 for minimum resistance to air flow and minimum exposure of their surfaces to the air fiow.

The disks in groups 158, 160 and 162 present succeedingly smaller surface areas to the air flow in the positions shown in FIG. 8. This staggering of the disks presents a substantially uniform motor load, a relatively uniform but low resistance to air flow, and a relatively constant overall rate of evaporation. It will be appreciated that all of the disks may be parallel as in FIG. 2 however.

In this embodiment, a certain amount of air turbulence is produced by the circuitous path which the air must follow and all of the air evaporates water from the five separate sets of disks for a very high increase in humidity. A substantially smaller maximum angle between the disks and the direction of air flow, for example is preferred to minimize the resistance to air flow.

It will be appreciated that the water absorbing disks of the various embodiments may be loacted in planes perpendicular to the shaft axis and that the shaft axis may be fixed in a position forming a small angle with a plane normal to the direction of air flow for a substantially constant rate of evaporation. Thus FIG. 9 shows a fourth embodiment of the invention which is generally similar to that shown in FIG. 2 except that the water absorbing disks are positioned in planes normal to the axis of the shaft, and the shaft is positioned diagonally in the air stream.

The humidifier 170 of FIG. 9 comprises a generally semi-cylindrical water reservoir 172 having projections 174 and 176 projecting horizontally outwardly from the upper end thereof. The projections 174 and 176 are secured to the lower wall 178 of a hot air duct 18% by means of a brace member 132 and fastening assem- Q is blies 184 in a manner generally similar to that shown in FIGS. 2 and 3 with respect to the first embodiment.

The projection 176 carries the motor drive assembly 186 for rotating a shaft 188 at a relatively low speed; and the shaft carries a plurality of screen wire disks 1% in planes generally perpendicular to the axis of the shaft. A switch 192, similar to switch of FIG. 4, energizes the motor drive assembly in response to air flow through the duct. It will be noted that the positions of the disks 190 as they are rotated by the motor assembly 186 do not change relative to the direction of air flow as in the previous embodiments. As a result the disks present the same amount of surface area to the air flow at all times.

FIGS. 10 and 11 show portions of a portable humidiher 2% embodying the teachings of the present invention. The humidifier 299 includes a housing 202 having a rectangular base 204, end walls 206 and 208 with rectangular lower portions and semi-circular upper portions, and a unitary side wall and cover member 210 mating with the end walls. The base, end walls and side walls are welded together for a water-tight fit permitting use of the lower portion of the housing as a water reservoir.

A motor assembly 212 is secured to the exterior of the end wall 2% and is connected to and drives a shaft 214. The shaft is journaled to the end wall 208 at 216. A plurality of disks 218 similar to disk of FIG. 5 are carried by the shaft at a small angle relative to a plane normal to the shaft axis. A plurality of spacers 22% having diagonal ends support the disks in spaced parallel relation.

The end walls 206 and 2'98 are provided with an air inlet opening 222 and an air outlet opening 224. A fan assembly 226 and a vertical heater stack of electric heater elements 228 are suitably carried by the cover member 210. The heater elements serve the same function as the heater elements 148 of the embodiment of FIG. 8. The housing is provided with means (not shown) to fill the Water reservoir and to indicate the water level as in the embodiment of FIG. 8.

A small spacing, preferably in the order of one-fourth inch, is provided between the juxtaposed edges of the disks 218 and the inner surface of the unitary cover and end wall member 219 to provide a path for air flow indicated by arrows. Since the air flow in this embodiment is more restricted than in the previous embodiments, the power requirements of the fan assembly 226 are preferably increased to compensate for the loss in air flow rate thereby providing a satisfactory rate of air flow through the humidifier. The restricted passages formed by the disk edges and the member 210 cause a swirling action of the air between adjacent disks to improve the evaporation efiiciency.

The word disk as used in the appended claims is I used in its broadest sense and is not intended to be limited to a circular disk.

The words water absorbing as applied to the disks in the appended claims are used in their broadest sense to mean a disk which will pick up water as it moves through the water reservoir and retain or carry the water with it as it moves into the air stream.

While there have been shown what are believed to be the preferred embodiments of the invention, it will be appreciated that various changes and modifications may be made therein; and it is contemplated to cover in the appended claims all such changes and modifications as fall within the true spirit and scope of the invention.

I claim:

1. An evaporative humidifier adapted to be supplied as a portion of a hot air furnace system comprising: means providing an air duct having a horizontal portion. a water reservoir disposed below the horizontal portion, said reservoir being open at the top to communi- Q i Wi h the pace within said horizontal duct portion,

a shaft mounted for rotation with its axis horizontal and in an attitude transverse to the direction of air flow through said duct portion and adjacent the top of said reservoir, a plurality of parallel discs of water-absorbing material and secured to said shaft in planes defining small acute angles with the plane normal to the axis of rotation of the shaft, the lower portions of the discs extending into the reservoir for absorbing water and the upper portions of said discs extending into the duct horizontal portion for the evaporation of water from said discs, drive means connected for rotating said shaft slowly, said discs having a plurality of equi-angularly spaced, radial, slots to provide a plurality of radially extending fingers and the material of which said discs are formed being sutficiently flexible so as to cause said fingers to vibrate under the influence of an air stream passing through said duct horizontal portion.

2. The combination called for in claim 1 in which the drive means rotates said shaft at a speed which is Within the range of from one to seven revolutions per minute.

3. The combination called for in claim 1 in which the material of which the discs are formed is metal screen wire.

4. The combination called for in claim 3 in which the drive means rotates said shaft at a speed which is Within the range of from one to seven revolutions per minute.

5. An evaporative humidifier adapted to be supplied as a portion of a hot air furnace system comprising: means providing an air duct having a horizontal portion, a water reservoir disposed below the horizontal portion, said reservoir being open at the top to communicate with the space within said horizontal duct portion, a shaft mounted for rotation with its axis horizontal and in an attitude transverse to the direction of air flow through said duct portion and adjacent the top of said reservoir, a plurality of parallel discs of water-absorbing material and secured to said shaft, the lower portions of the discs extending into the reservoir for absorbing water and the upper portions of said discs extending into the duct horizontal portion for the evaporation of water from said discs, drive means connected for rotating said shaft slowly, said discs having a plurality of equi-angularly spaced radial slots to provide a plurality of separate fingers, and the material of which said discs are formed being sufliciently flexible so as to cause said fingers to vibrate under the influence of an air stream passing through said duct horizontal portion.

6. The combination called for in claim 5 in which the material of which the discs are formed is metal screen Wire.

7. The combination called for in claim 5 in which the drive means rotates said shaft at a speed which is Within the range of from one to seven revolutions per minute.

References Cited by the Examiner UNITED STATES PATENTS 1,345,131 6/20 Cleworth 261-92 1,844,942 2/32 Buttfield 261-92 2,021,521 11/35 Sargent 261-142 2,094,456 9/37 Lattner 261-92 2,221,003 11/40 Massey 261-92 2,324,386 7/43 Gusy 261-92 2,508,839 5/50 Roe 261-92 FOREIGN PATENTS 192,120 11/07 Germany. 677,432 8/52 Great Britain.

HARRY B. THORNTON, Primary Examiner. HERBERT L. MARTIN, Examiner. 

5. AN EVAPORATIVE HUMIDIFIER ADAPTED TO BE SUPPLIED AS A PORTION OF A HOT AIR FURNACE SYSTEM COMPRISING: MEANS PROVIDING AN AIR DUCT HAVING A HORIZONTAL PORTION, A WATER RESERVOIR DISPOSED BELOW THE HORIZONTAL PORTION, SAID RESERVOIR BEING OPEN AT THE TOP TO COMMUNICATE WITH THE SPACE WITHIN SAID HORIZONTAL DUCT PORTION, A SHAFT MOUNTED FOR ROTATION WITH ITS AXIS HORIZONTAL AND IN AN ATTITUDE TRANSVERSE TO THE DIRECTION OF AIR FLOW THROUGH SAID DUCT PORTION AND ADJACENT THE TOP OF SAID RESERVOIR, A PLURALITY OF PARALLEL DISCS OF WATER-ABSORBING MATERIAL AND SECURED TO SAID SHAFT, THE LOWER PORTIONS OF THE DISCS EXTENDING INTO THE RESERVOIR FOR ABSORBING WATER AND THE UPPER PORTIONS OF SAID DISCS EXTENDING INTO THE DUCT HORIZONTAL PORTION FOR THE EVAPORATION OF WATER FROM SAID DISCS, DRIVE MEANS CONNECTED FOR ROTATING SAID SHAFT SLOWLY, SAID DISC HAVING A PLURALITY OF EQUI-ANGULARLY SPACED RADIAL SLOTS TO PROVIDE A PLURALITY OF SEPARATE FINGERS, AND THE MATERIAL OF WHICH SAID DISCS ARE FORMED BEING SUFFICIENTLY FLEXIBLE SO AS TO CAUSE SAID FINGERS TO VIBRATE UNDER THE INFLUENCE OF AN AIR STREAM PASSING THROUGH SAID DUCT HORIZONTAL PORTION. 